1. Field of the Invention
The present invention relates to a radio device, for instance, like a television receiver, which connects between an antenna unit and a device main unit via a cable such as a coaxial cable.
2. Description of the Related Art
In general, a television broadcast receiver is composed of an antenna unit, and a device main unit with a receiving circuit, an image processing circuit, a display unit, etc. incorporated therein. In the case of a stationary type, the device main unit is set within doors, the antenna unit is set out of doors, and these units are connected via such a cable as a coaxial cable. Like this, the setting of the antenna unit out of doors or the outside of a vehicle enables maintaining reception sensitivity high (for example, refer to Jpn. Pat. Appln. KOKAI Publication No. 5-161140).
However, the television broadcast receiver cannot obtain desired reception sensitivity depending on the setting state of the antenna unit, and especially, in the case of terrestrial digital broadcast, it cannot receive at all sometimes. This case is apt to be caused particularly when a user set up the receiver by himself. In such a case, it is impossible for the user to distinguish whether a cause that broadcast cannot be received comes from a reception defect depending on the setting state, etc. of the antenna unit or from a wrong connection of wiring between the antenna unit and the device main unit.